just the same way that a closed topic is indicated in the topic list with a lock, it would be good if topics with a future timing can also be shown.
something like this, if the “Troubleshooting email on a new install” topic, was going to be closed in 1 hour from now:
Not a bad idea but I feel it’s a bit visually noisy relative to the weak value of the information presented.
what about showing the timer when only less than 24 (or 12) hours is remained? this way the timer is only shown for less than 1 day (after that it’ll be a lock). Also it emphasizes to the users that:
there’s a little time remaining, if you want to contribute, please help yourself faster.
That might be OK. At SitePoint the majority of categories are set to “close 3 months after the last reply” so having the icon for every topic that had timing would be very
I’m not super convinced users treat it as a race to see who can reply before the topic closes. Usually the topic closing is background administrative trivia, it is not a contest with winners to see who can post nearest the close time 
One interesting case where a similar concept would be very useful would be for buy/sell categories. When you have 1 day left you do want to call it out big time. But I wonder if “auto title updating” is a better type of feature here for a buy/sell plugin:
Red rockstar boots, $44 (Ending in 2 hours)
Usually you sort by ending soonest, instead.
some use cases which may fit this concept:
ideation challenges,
some community management topics, e.g. “what have you done this week?”
marketplaces,
moderation actions where something from the user side can undo the moderation;
e.g. a bug is set to be closed after being solved, unless users report similar issues again in 12 hours.
our main use case is about some free discussion, where we choose a topic and discuss about it for 3 days. to keep these discussion organized, it’s a one discussion at a time. so every discussion is closed automatically after 3 days. since there’s no indicator in the topic list, sometimes users forget about the timing and their inputs are being dismissed, even if they have saved drafts to discuss.
our use-case is not about the contest, but more about a notification.
